Patent application US 2004068037 describes blends of polyamides and clays. In the process of the invention, a polyamide A1 and an organized clay B are mixed mainly by dispersive mixing, and after added with a polyamide A2, mixed mainly by distributive mixing in a corotating intermeshing twin-screw extruder so designed as to effect the dispersive mixing and the distributive mixing. The organized clay B is completely and finely dispersed and distributed throughout the resultant polyamide composite material. Shaped articles such as films and sheets made of the polyamide composite material exhibit excellent gas barrier properties and transparency with little malodor mainly attributable to the decomposed products of the organizing agent for preparing the organized clay B.
Patent U.S. Pat. No. 5,578,672 describes polymers containing intercalated layered materials. More particularly, the present invention is directed to intercalates having at least two layers of oligomer and/or polymer molecules sorbed on the internal surfaces of adjacent layers of the planar platelets of a layered material, such as a phyllosilicate, preferably a smectite clay. The resulting matrix polymer/platelet composite materials are useful wherever polymer/filler composite materials are used, for example, as external body parts for the automotive industry; heat-resistant polymeric automotive parts in contact with an engine block; tire cord for radial tires; food wrap having improved gas impermeability; electric components; food grade drink containers; and any other use where it is desired to alter one or more physical properties of a matrix polymer, such as elasticity and temperature characteristics, e.g., glass transition temperature and high temperature resistance.
Japanese patent application JP2000086822 describes a resin composite material for hose material, isolator, it has organic clay dispersed in at least single segments of the block copolymer type thermoplastic elastomer which consists of many segments.
Japanese patent application JP 11310643 describes the manufacture of thermoplastic polymer-clay composite materials with good gas-barrier properties.
Japanese patent application US 4835065 describes a polyamide resin compositions for films for wrapping food-comprise lamellar silicates uniformly dispersed in copolymerised polyamide resin.
Japanese patent application US 4835065 describes a polyamide resin compositions for films having gas barrier properties made by uniformly dispersing lamellar silicate into resin consisting of aromatic and aliphatic polyamide resins.
Japanese patent application JP 03262633 describes the production of polyamide film useful for good packaging comprises of drawing polyamide containing evenly dispersed sheet silicate and having low water content.
Japanese patent application JP 04178459 describes a resin composition for stretched polyamide film comprises polyamide resin, silicate salts, hindered phenol series compound and silane for titanate coupling agent.
Japanese patent application JP 04080259 describes a resin composition of stretched polyamide film consists of polyamide resin, lamellar silicate and silane and/or titanate coupling agent.
Japanese patent application JP 08073734 describes a resin composition of polyamide for film practice for wrapping film containing inorganic filler, and mixture of zin oxide and basic aliphatic acid salt of magnesium. The resin composition has a controlled phase structure of resin in the exfoliated surfaces of the fillers.
European patent application US 5102948 describes a polyamide composite material containing layered slicate uniformly dispersed in the polyamide.
German patent application US 6117932 describes a resin composite including organophilic clay and functionalized (co)polymer, useful for injection, extrusion, blown and compression molding and for films.
Patent application US 2004-0225066 describes polyamide and polyolefin blends with a polyamide matrix and containing nanofillers. These blends are thermoplastic and can be converted to bottles, reservoirs, containers, pipes and vessels of all sorts. It also relates to structures comprising at least one layer of these blends and at least one layer of another material. These structures can be converted to bottles, reservoirs, containers, pipes and vessels of all sorts. All these objects exhibit good barrier properties. For example, foods packaged in these packagings are protected from atmospheric oxygen and their degradation is avoided, whereas a polyethylene packaging allows some oxygen to pass through and the foods undergo degradation. The barrier properties can also be used in another sense. Thus, in the Sheet Moulding Compound (SMC) technology, a composition based on crosslinkable unsaturated polyester and on styrene is disposed between two films and it is necessary for the styrene to remain in the composition and not to diffuse through the films. It is also possible to mention the barrier to pentane which is useful in packaging containing expandable polystryrene beads. Indeed, these beads contain pentane and it is necessary that the beads do not lose their pentane before their conversion to expanded polystyrene. It is also possible to mention pipes in which the cryogenic fluids for air conditioning circulate, such as for example HFAs and HFCs. In an air conditioning device, loss of fluid should be reduced both for economic reasons (these fluids are expensive) and for environmental protection reasons (an excessive leakage could damage the ozone layer).
European patent application US 5248720 describes a material for molded article and film having liquid or gas barrier property. It is a mixture containing a polyamide resin or a resin mixture containing a polyamide resin and a layered silicate uniformly dispersed therein. The material for molding of said patent is applicable for various uses requiring liquid or gas barrier property. Examples of applicable uses may include, but are not limited to, a gasoline tank, alcohol tank, fuel tube, fuel strainer, brake oil tank, clutch oil tank, power steering oil tank, Freon tube for a cooler, Freon tank, canister, air cleaner, intake system parts, etc. In example 1 one hundred grams of montmorillonite were dispersed in 10 liters of water, then 51.2 g of 12-aminododecanoic acid and 24 ml of concentrated hydrochloric acid were added and the mixture was stirred for 5 minutes, followed by filtration. Then, the filtered product was thoroughly washed and vacuum dried. By this operation, a composite of 12-aminododecanoic acid ammonium ion and montmorillonite was prepared. Next, into a reaction vessel equipped with a stirrer, 10 kg of ε-caprolactam, 1 kg of water and 100 g of the above composite were charged, and the mixture was stirred so that the reaction system became internally uniform at 100° C. Further, the temperature was raised up to 260° C., and the mixture was stirred under pressurization of 15 kg/cm2 for one hour. Then, the pressure was released, and while the water was evaporated from the reaction vessel, the reaction was carried out under normal pressure for 3 hours. After completion of the reaction, the reaction product was taken out in strands from the bottom nozzle of the reaction vessel and was water-cooled and subjected to cutting to obtain pellets comprising a polyamide resin (average molecular weight 15,000) and montmorillonite. The pellets were immersed in hot water to extract and remove unreacted monomer (about 10%), followed by drying in vacuum, to give a material for a molded article. The material for a molded article was extrusion molded under the following conditions to prepare a tube with an outer diameter of ½ inch and a thickness of 1 mm, then permeability to Freon R22 was measured. All other examples are similarly based on a first mixing of montmorillonite with 12-aminododecanoic acid then with caprolactam. An example describes a bottle having an outer layer of composition above (PA 6 and montmorillonite), a tie layer and a polyethylene inner layer. Barrier properties of said bottle to gasoline are measured.
The previous art has not described multi-layers comprising at least a layer of a thermoplastic compound containing nanofillers and at least a layer of rubber.
In the two main methods of producing AC hoses for automotive application (Barrier and Veneer) the emphasis has been placed on producing compounds with better permeation to refrigerant. This invention however, takes advantage of increasing the path (tortures path) a diffusing gas will take to go through the tubing wall. This invention utilizes, by way of example, the improved gas barrier of a polyamide 6,66 copolymer when activated nano-clay is added to this material as an AC hose where the refrigerant going through the tubing made from this material is 134a.